osmo-mgw's configure.ac won't find osmotestvty.py, unless it is
executable. This allows passing its ./configure with placing the scripts
dir of osmo-python-tests in PATH, instead of installing it.
Change-Id: If6cefd32d0dc544093db08efc114db86b9bb18b0
Use proper print() function to make scripts compatible with both python
2 and 3. This paves the way to deprecating python 2 support altogether.
Change-Id: I80e5850a8978d78cda793e2192ef4bd3fd54a121
Having the scripts in the same directory with library code means that
it'll be installed unconditionally regardless of version check in
setup.py which makes it impossible to write separate tests for python 2
and 3. Fix this by moving the scripts into separate directory and
adjusting init and setup files accordingly.
This is necessary for implementing proper CI tests in follow-up patches.
Change-Id: I30cdf0f85b2a60a235960911c9827f4129da40db